blink: Cleanup class forward declarations

third_party/WebKit/Source/platform/graphics/AcceleratedStaticBitmapImage.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef AcceleratedStaticBitmapImage_h
 #define AcceleratedStaticBitmapImage_h
 
 #include "base/threading/thread_checker.h"
 #include "platform/geometry/IntSize.h"
 #include "platform/graphics/StaticBitmapImage.h"
 #include "third_party/skia/include/core/SkRefCnt.h"
 
 #include <memory>
 
 class GrContext;
 
-namespace cc {
-class SingleReleaseCallback;
-}
-
 namespace blink {
 class WebThread;
 
 class PLATFORM_EXPORT AcceleratedStaticBitmapImage final
     : public StaticBitmapImage {
  public:
   // SkImage with a texture backing that is assumed to be from the shared
   // context of the current thread.
   static PassRefPtr<AcceleratedStaticBitmapImage> createFromSharedContextImage(
       sk_sp<SkImage>);
@@ skipping 59 matching lines @@
   // after a transfer.
   WebThread* m_imageThread = nullptr;
 
   base::ThreadChecker m_threadChecker;
   bool m_detachThreadAtNextCheck = false;
 };
 
 }  // namespace blink
 
 #endif